/Engine/Plugins/FX/Niagara/Source/NiagaraShader/Public/NiagaraShaderParametersBuilder.h
Adds a shader parameters structure that is global in scope i.e. if the structure contained "MyFloat" the shader variable would be named "MyFloat"
void AddIncludedStruct ( const [FShaderParametersMetadata](API\Runtime\RenderCore\FShaderParametersMetadata) * StructMetadata )